Description

The dlpi_enabnotify() function enables a notification callback for the set of events
specified in notes, which must be one or more (by a logical
OR operation) of the DLPI notifications documented in dlpi(7P). The
callback function funcp is registered with the DLPI handle dh and is
invoked when dh receives notification for any of the specified event types.
Upon success, id contains the identifier associated with the registration.

Multiple event types can be registered for a callback function on the
DLPI handle dh. Similarly, the same event type can be registered multiple
times on the same handle.

Once a callback has been registered, libdlpi will check for notification events
on the DLPI handle dh, when exchanging DLPI messages with the underlying
DLPI link instance. The dlpi_recv(3DLPI) function will always check for notification events,
but other libdlpi operations may also lead to an event callback being
invoked. Although there may be no expected data messages to be received,
dlpi_recv() can be called, as shown below, with a null buffer to force
a check for pending events on the underlying DLPI link instance.

dlpi_recv(dh, NULL, NULL, NULL, NULL, 0, NULL);

When a notification event of interest occurs, the callback function is invoked
with the arguments arg, originally passed to dlpi_disabnotify(3DLPI), and infop, whose members are
described below.

uint_tdni_note

Notification event type.

uint_tdni_speed

Current speed, in kilobits per second, of the DLPI link. Valid only for DL_NOTE_SPEED.

uint_tdni_size

Current maximum message size, in bytes, that the DLPI link is able to accept for transmission. Valid only for DL_NOTE_SDU_SIZE.

uchar_tdni_physaddrlen

Link-layer physical address length, in bytes. Valid only for DL_NOTE_PHYS_ADDR.

uchar_tdni_physaddr[]

Link-layer physical address of DLPI link. Valid only for DL_NOTE_PHYS_ADDR.

The libdlpi library will allocate and free the dlpi_notifyinfo_t structure and the
caller must not allocate the structure or perform any operations that require
its size to be known.

The callback is not allowed to block. This precludes calling dlpi_enabnotify()
from a callback, but non-blocking libdlpi functions, including dlpi_disabnotify(), can be called.

Return Values

Upon success, DLPI_SUCCESS is returned. If DL_SYSERR is returned,
errno contains the specific UNIX system error value.
Otherwise, a DLPI error value defined in <sys/dlpi.h> or an error value listed
in the following section is returned.